Drawing-board.



A. G. BORNTRAEGER.

DRAWING BOARD APPLICATION HLED APR. 19.1913. RENEWED NOV. 5. 1915.

LIMQS. Patented Dec.14,1915.

Z SHEETSSHEET A. e. BORNTHAEGER.

DRAWING BOARD! APPLICATION FILED APR. 19.1913. RENEWED NOV. 5. 19I5.

1,16%,Q53u Patented Dec. 14, 1915.

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DRAWING-BOARD.

menses.

Specification of Letters Patent.

Application filed April 19, 1913, Serial No. 762,383. Renewed November 5, 1915., Serial No. 59,885.

To all whom it may concern:

Be it known that I ARTHUR G. Bonn- TRAEGER, citizen of the United States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented certain new and useful Improvements 1n Drawing-Boards, of which the following is a specification. I t

This invention relates to an improved drawing board of the rotatable type wherein means is provided for vertically ad ust1ng a straight-edge thereupon, the provision ofthe said straight-edge adapted to eliminate the necessity of using T-squares, protractors, dividers, triangles, etc, now commonly used in connection with drawing boards.

A further object of the invention contemplates the provision of means including a suitable indicator or gage whereby any degree of angle may be quickly ascertained by simply rotating the board, the indlcating mechanism being carried by the said board and actuated according to the rotation thereof.

The invention still further resides in the provision of an adjustable pencil holder adapted to be laterally slid upon the straight-edge employed in connection with the drawing boards whereby circles of various sizes may be described from the center of the board by simply rotating the same.

A still further object of the invention is to provide means including an endless cord or other element for retaining and adJuSting the straight-edge upon the drawing board as occasion demands, the said endless cord being arranged in a novel and peculiar manner over suitable pulleys disposed at various oints upon the supporting frame of the device.

The above and additional objects are accomplished bv such means as are illustrated in their preferred embodiment in the accompanying drawings, described in the following specification and then more partlcularly pointed out in the claims which are appended hereto and form a part of thls application.

In describing my invention in detail reference will be had to the accompanying drawings wherein like characters denote like or corresponding parts throughout the several views, and in which:

' Figure 1 is a plan view of the draw ng board and its supporting frame, both being n u ed in e danee hn l a ea tion; Fig. 2 is an edge view, partly broken away; Fig. 3 is an enlarged detail sectional Fig.4 is an enlarged top view of the pencil holder or carrier; Fig. 5 1s a similar View of the indicator; Fig. 6 isa section on line 6-6 of Fig. 5; and Fig. 7 is a detail sectionalview taken on line 77 of Fig. 4.

Referring now to the drawings wherein is illustrated the preferred form of my invention the numeral 1 designates the drawing board proper which is revolubly or rotatablymounted upon a suitable supporting frame 2 through the medium of rollers 3 carried by the said frame, the rollers being adapted to engage the periphery of an annular plate or disk 4 secured to the under side of the drawing board 1, the latter being normally supported in a substantially vertical position. Vertically extending frame sides 5 are secured to the supporting frame 2 and have revolubly mounted thereupon suitable pulleys 6, the saidpulleys being disposed in spaced apart openings 7 formed within the upper extremity of the frame sides 5. A second pulley 8 is arranged upon each of the frame sides 5 near the base thereof, all

of the said pulleys being adapted to form a guide over which the straight-edge supporting element 9 is arranged, the said element being preferably composed of an endless cord. That portion of the cord Qbetween the upper extremities of the frame sides 5 is crossed near the center and has secured thereto suitable springs 10 for normally retaining the said cord in taut condition and causing the straight-edgell which is secured thereto by means of suitable blocks 12, to be vertically slid throughout the greater portion of the length of the frame sides 5 according to the movement of the said cord 9. By crossing the cord 9 at the top of the frame 2 it will be seen that that portion of the said cord to which the blocks 12 are secured always travels in the same direction and will in this manner always support the straight-edge at right angles to the frame sides 5. r t

The straight-edge 11is provided with a dove-tail groove 13 extending throughout the Patented Dec. 14L, T915.

said beam. A vertically extending scale 16 is arranged at oneside of theframe 2 so as to extend parallel with one ofthe frame sides 5 against which it is normally heldby meansof suitable pins 17 extending through elongated slots 18 of the said beam for adjustably supporting the latter upon the frame 2 of the device.

Referring now to the indicating mechanism, designated in its entirety by the .numeral 19, the same preferably comprises a suitable casing20 adapted to be secured as at 21 to the drawing board 1 at one side thereof. An indicator hand 22 is loosely mounted upon a suitable shaft 23 carried by the casing 20 for indicating upon a dial 24 the angular adjustment of the said drawing board 1 with respect to the straight edge 11. By providing theindicator 22 with a weight'member 23 at one end thereof the same is at all times supported ina vertical position thereby allowing the dial 2% to be moved beneath the said handle according to'the movement of the drawing board to which it is attached. Graduation marks 25 are arranged upon the dial 24 indicating degrees ranging from 1 to 90 as is clearly illustrated in Fig. 5 of the drawings. To protect the indicator hand and the dial therefor, a glass covering 26 is carried by the casing 20 thus insuring a perfect operation of the indicator hand at all times.

A pencil holder or carrier 27 is adjustably mounted upon the straight-edge 11 the latter passing therethrough as is clearly shown in Fig. 7 of the drawings for the purpose of sliding the said carrier upon the straightedge throughout the length thereof. A pencil holder 28 is arranged upon the carrier 27, the said holder having a pointed end 29 adapted to register with the graduation I 'marks of the scale beam 14 for adjusting the said pencil holder with respect to the straight-edge as desired. A spring member 30 is formed integrally with and upon the extremity of the holder 28 through which the drawing pencil (not shown) extends, the point thereof being adapted to engage the drawing paper secured to the drawing surface of the board. Guide blocks 31 are adjustably mounted through the medium of a thumb-nut 32 in a right and left hand for the purpose of attaching the drawing sheet to the drawing board, the said strips extending over and beyond the edges of the said board where they are supported in immovable position by means of the spring tension generated from the spring material from which the strips are composed.

Having described fully the detail structure of the drawing board and the support ing means the operation thereof will now be set forth. The drawing sheet is first secured upon the drawing surface of the board 1 by means of the spring strips 37 above described whereupon the straight-edge is adjusted by the operation of the cord 9 to the desired position with respect to the paper carried by the board. Vertical, horizontal or oblique lines may be measured and arranged upon the drawing sheet by rotating the drawing board 1 upon the frame 2 by means of whichit is supported. Minute adjustment of the vertically extending scale beams 16 may be provided by the manipulation of the pins or thumb-nuts 17 which extend throughthe slots 18 of the said beam, while minute adjustment of the scale beam 1 1 is permitted by the manipulation of the thumb-screw 15 extending therethrough.

The indicating mechanism 19 will permit the drawing of lines upon angles of various degrees without the use of calipers or other implements, as the hand 22 of the said indicating mechanism always indicates the degree of angular adjustment of the board with respect to the cooperating straightedge. The provision of the pencil holder .28 will permit circles of various sizes to be described upon the board by simply rotating the latter after the carrier 27 has been first adjusted upon the straight-edge 11 of the device. It will readily be noted, in this 'latter connection, that the adjusting blocks 31 may be so positioned with respect to the carrier that one edge of the latter may contact with one of the blocks and the board rotated to scribe a circle while by shifting the carriage with respect to the blocks so that the other edge contacts with the other block, a second and concentric circle may be scribed the size of which with respect to the first circle has been determined by the distance separating the blocks. This forms a ready means for determining the difference in radii of concentric circles which may be drawn by the apparatus.

It will be seen from the above, taken in connection with the accompanying drawings that the provision of the springs 10 will at all times assure a taut supporting means for the straight-edge 11; that the various implements now employed in connection with the drawing boards as at present constructed can be dispensed with without decreasingthe efliciency or in any way affecting the result obtained; and that any suitable means or standard may be employed in connection with the supporting frame for elevating the board in the desired height and in the desired manner.

In reduction to practice, I have found that the form of my invention, illustrated in the drawings and referred to in the above description, as the preferred embodiment, is the most efficient and practical; yet realizing that the conditions concurrent with the adoption of my device will necessarily Vary, I desire to emphasize the fact that various minor changes in details of construction, proportion and arrangement of parts may be resorted to, when required, without sacrificing any of the advantages of my invention, as defined in the appended claims.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is

1. In combination with a drawing board, a supplementary frame therefor, means rotatably mounting said board on said frame, a straight edge carried by said frame, a scale beam movable over said straight edge and said board, a carrier slidably mounted upon said scale beam, a pencil holder arranged upon said carrier and provided with an indicating point registering with said scale beam, blocks adjustably mounted within said carrier to similarly register with said beam, and means for correlating the action of said blocks with respect to the surrounding edge of said carrier and said indicating point to determine the difference 1n radii of concentric circles to be drawn.

2. In combination with a drawing board, a supplementary frame therefor, means rotatably mounting said board on said frame, a straight edge carried by said frame, a scale beam movable over said straight edge and said board, a carrier slidably mounted upon said scale beam, a pencil holder arranged upon said carrier and provided withan indicating point registering with said scale beam, blocks adjustably mounted within said carrier to similarly register with said beam, means for arranging said blocks with respect to said carrier and said indicating point to determine the difference in radii of concentric circles to be drawn, and an indicating mechanism including a pointer normally seeking a single directionand an arcuate scale rotatable with said board with respect to said pointer to indicate degrees of angular adjustment of said board.

3. In combination with a drawing board, a supplementary frame upon which said board is rotatably mounted, a straight-edge carried by the said frame, means including an endless cord secured to the respective extremities of said straight-edge for adjusting the same laterally upon the said frame, a scale being carried by the said frame at one side thereof for measuring the adjustment of the said straight-edge, a second scale being dove-tailed into the said straightedge and longitudinally adjustable thereupon, a carrier slidably mounted upon the said scale beam, a pencil holder arranged upon the said carrier, the movement of the said holder being determined by the graduation marks of the said second mentioned scale beam, adjustable blocks mounted within the said carrier, and means including indicating mechanism carried by the said drawing board adapted to indicate the degree of angular adjustment of the said board with respect to the said straight-edge.

4. In combination with a drawing board, a straight-edge having a dove-tailed groove extending longitudinally throughout the length thereof, a dove-tailed rule being adjustable longitudinally upon the said straight-edge and within the said groove, a carrier slidable throughout the length of the said straight-edge, means including a pair of adjustable blocks carried upon the said carrier, the said blocks being adapted to be moved over the said scale beam for measuring distances thereupon, and means including an endless flexible element carried by the said drawing board and connected to the respective extremities of the said straight-edge for adjusting the latter vertically thereover, as and for the purpose set forth.

5. In combination with a drawing board, a frame therefor, a straight-edge vertically adjustable over the said board, a single end-v less element carried by the said frame and connected to the respective extremities of the said straight-edge for adjusting the same vertically with respect to said board, a longitudinally adjustable scale beam dovetailed within the said straight-edge, a slidable carrier arranged to embrace the said straight-edge, an adjustable block mounted within the said carrier directly over the said scale beam for measuring distances thereupon, and means including a pencil holder carried by the said carrier, as and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

ARTHUR G. BORNTRAE GER.

Witnesses:

HENRY A. RITTY, CLARA QUARTERMAN.

IUOpies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

- Washington, D. G. 

